Add --exclude-database option to pg_dumpall

This option functions similarly to pg_dump's --exclude-table option, but
for database names. The option can be given once, and the argument can
be a pattern including wildcard characters.

Author: Andrew Dunstan.
Reviewd-by: Fabien Coelho and Michael Paquier
Discussion: https://postgr.es/m/43a54a47-4aa7-c70e-9ca6-648f436dd6e6@2ndQuadrant.com

doc/src/sgml/ref/pg_dumpall.sgml

@@ -311,6 +311,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+
+     <varlistentry>
+      <term><option>--exclude-database=<replaceable class="parameter">pattern</replaceable></option></term>
+      <listitem>
+       <para>
+        Do not dump databases whose name matches
+        <replaceable class="parameter">pattern</replaceable>.
+        Multiple patterns can be excluded by writing multiple
+        <option>--exclude-database</option> switches.  The
+        <replaceable class="parameter">pattern</replaceable> parameter is
+        interpreted as a pattern according to the same rules used by
+        <application>psql</application>'s <literal>\d</literal>
+        commands (see <xref
+        linkend="app-psql-patterns" endterm="app-psql-patterns-title"/>),
+        so multiple databases can also be excluded by writing wildcard
+        characters in the pattern.  When using wildcards, be careful to
+        quote the pattern if needed to prevent shell wildcard expansion.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--if-exists</option></term>
       <listitem>

src/bin/pg_dump/pg_dump.c

@@ -1301,7 +1301,8 @@ expand_schema_name_patterns(Archive *fout,
 
 /*
  * Find the OIDs of all tables matching the given list of patterns,
- * and append them to the given OID list.
+ * and append them to the given OID list. See also expand_dbname_patterns()
+ * in pg_dumpall.c
  */
 static void
 expand_table_name_patterns(Archive *fout,

src/bin/pg_dump/pg_dumpall.c

@@ -52,6 +52,8 @@ static PGconn *connectDatabase(const char *dbname, const char *connstr, const ch
 static char *constructConnStr(const char **keywords, const char **values);
 static PGresult *executeQuery(PGconn *conn, const char *query);
 static void executeCommand(PGconn *conn, const char *query);
+static void expand_dbname_patterns(PGconn *conn, SimpleStringList *patterns,
+								   SimpleStringList *names);
 
 static char pg_dump_bin[MAXPGPATH];
 static const char *progname;
@@ -87,6 +89,9 @@ static char role_catalog[10];
 static FILE *OPF;
 static char *filename = NULL;
 
+static SimpleStringList database_exclude_patterns = {NULL, NULL};
+static SimpleStringList database_exclude_names = {NULL, NULL};
+
 #define exit_nicely(code) exit(code)
 
 int
@@ -123,6 +128,7 @@ main(int argc, char *argv[])
 		{"column-inserts", no_argument, &column_inserts, 1},
 		{"disable-dollar-quoting", no_argument, &disable_dollar_quoting, 1},
 		{"disable-triggers", no_argument, &disable_triggers, 1},
+		{"exclude-database", required_argument, NULL, 6},
 		{"extra-float-digits", required_argument, NULL, 5},
 		{"if-exists", no_argument, &if_exists, 1},
 		{"inserts", no_argument, &inserts, 1},
@@ -324,6 +330,10 @@ main(int argc, char *argv[])
 				appendShellString(pgdumpopts, optarg);
 				break;
 
+			case 6:
+				simple_string_list_append(&database_exclude_patterns, optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 				exit_nicely(1);
@@ -340,6 +350,16 @@ main(int argc, char *argv[])
 		exit_nicely(1);
 	}
 
+	if (database_exclude_patterns.head != NULL &&
+		(globals_only || roles_only || tablespaces_only))
+	{
+		fprintf(stderr, _("%s: option --exclude-database cannot be used together with -g/--globals-only, -r/--roles-only or -t/--tablespaces-only\n"),
+				progname);
+		fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
+				progname);
+		exit_nicely(1);
+	}
+
 	/* Make sure the user hasn't specified a mix of globals-only options */
 	if (globals_only && roles_only)
 	{
@@ -454,6 +474,12 @@ main(int argc, char *argv[])
 		}
 	}
 
+	/*
+	 * Get a list of database names that match the exclude patterns
+	 */
+	expand_dbname_patterns(conn, &database_exclude_patterns,
+						   &database_exclude_names);
+
 	/*
 	 * Open the output file if required, otherwise use stdout
 	 */
@@ -620,6 +646,7 @@ help(void)
 	printf(_("  --column-inserts             dump data as INSERT commands with column names\n"));
 	printf(_("  --disable-dollar-quoting     disable dollar quoting, use SQL standard quoting\n"));
 	printf(_("  --disable-triggers           disable triggers during data-only restore\n"));
+	printf(_("  --exclude-database=PATTERN   exclude databases whose name matches PATTERN\n"));
 	printf(_("  --extra-float-digits=NUM     override default setting for extra_float_digits\n"));
 	printf(_("  --if-exists                  use IF EXISTS when dropping objects\n"));
 	printf(_("  --inserts                    dump data as INSERT commands, rather than COPY\n"));
@@ -1358,6 +1385,48 @@ dumpUserConfig(PGconn *conn, const char *username)
 	destroyPQExpBuffer(buf);
 }
 
+/*
+ * Find a list of database names that match the given patterns.
+ * See also expand_table_name_patterns() in pg_dump.c
+ */
+static void
+expand_dbname_patterns(PGconn *conn,
+					   SimpleStringList *patterns,
+					   SimpleStringList *names)
+{
+	PQExpBuffer query;
+	PGresult   *res;
+
+	if (patterns->head == NULL)
+		return;					/* nothing to do */
+
+	query = createPQExpBuffer();
+
+	/*
+	 * The loop below runs multiple SELECTs, which might sometimes result in
+	 * duplicate entries in the name list, but we don't care, since all
+	 * we're going to do is test membership of the list.
+	 */
+
+	for (SimpleStringListCell *cell = patterns->head; cell; cell = cell->next)
+	{
+		appendPQExpBuffer(query,
+						  "SELECT datname FROM pg_catalog.pg_database n\n");
+		processSQLNamePattern(conn, query, cell->val, false,
+							  false, NULL, "datname", NULL, NULL);
+
+		res = executeQuery(conn, query->data);
+		for (int i = 0; i < PQntuples(res); i++)
+		{
+			simple_string_list_append(names, PQgetvalue(res, i, 0));
+		}
+
+		PQclear(res);
+		resetPQExpBuffer(query);
+	}
+
+	destroyPQExpBuffer(query);
+}
 
 /*
  * Dump contents of databases.
@@ -1395,6 +1464,15 @@ dumpDatabases(PGconn *conn)
 		if (strcmp(dbname, "template0") == 0)
 			continue;
 
+		/* Skip any explicitly excluded database */
+		if (simple_string_list_member(&database_exclude_names, dbname))
+		{
+			if (verbose)
+				fprintf(stderr, _("%s: excluding database \"%s\"...\n"),
+						progname, dbname);
+			continue;
+		}
+
 		if (verbose)
 			fprintf(stderr, _("%s: dumping database \"%s\"...\n"), progname, dbname);
 

src/bin/pg_dump/t/001_basic.pl

@@ -4,7 +4,7 @@ use warnings;
 use Config;
 use PostgresNode;
 use TestLib;
-use Test::More tests => 70;
+use Test::More tests => 74;
 
 my $tempdir       = TestLib::tempdir;
 my $tempdir_short = TestLib::tempdir_short;
@@ -150,3 +150,14 @@ command_fails_like(
 	qr/\Qpg_restore: options -C\/--create and -1\/--single-transaction cannot be used together\E/,
 	'pg_restore: options -C\/--create and -1\/--single-transaction cannot be used together'
 );
+
+command_fails_like(
+	[ 'pg_dumpall', '--exclude-database' ],
+	qr/\Qpg_dumpall: option '--exclude-database' requires an argument\E/,
+	'pg_dumpall: option --exclude-database requires an argument');
+
+# also fails for -r and -t, but it seems pointless to add more tests for those.
+command_fails_like(
+	[ 'pg_dumpall', '--exclude-database=foo', '--globals-only' ],
+	qr/\Qpg_dumpall: option --exclude-database cannot be used together with -g\/--globals-only\E/,
+	'pg_dumpall: option --exclude-database cannot be used together with -g/--globals-only');

src/bin/pg_dump/t/002_pg_dump.pl

@@ -224,6 +224,12 @@ my %pgdump_runs = (
 			"--file=$tempdir/pg_dumpall_dbprivs.sql",
 		],
 	},
+	pg_dumpall_exclude => {
+		dump_cmd => [
+			'pg_dumpall', '-v', "--file=$tempdir/pg_dumpall_exclude.sql",
+			'--exclude-database', '*dump*', '--no-sync',
+		],
+	},
 	no_blobs => {
 		dump_cmd => [
 			'pg_dump',                      '--no-sync',
@@ -380,6 +386,7 @@ my %full_runs = (
 	no_owner                 => 1,
 	no_privs                 => 1,
 	pg_dumpall_dbprivs       => 1,
+	pg_dumpall_exclude       => 1,
 	schema_only              => 1,);
 
 # This is where the actual tests are defined.
@@ -444,6 +451,7 @@ my %tests = (
 			pg_dumpall_dbprivs       => 1,
 			pg_dumpall_globals       => 1,
 			pg_dumpall_globals_clean => 1,
+			pg_dumpall_exclude       => 1,
 		},
 	},
 
@@ -1318,6 +1326,7 @@ my %tests = (
 		regexp       => qr/^CREATE ROLE regress_dump_test_role;/m,
 		like         => {
 			pg_dumpall_dbprivs       => 1,
+			pg_dumpall_exclude       => 1,
 			pg_dumpall_globals       => 1,
 			pg_dumpall_globals_clean => 1,
 		},
@@ -2442,6 +2451,7 @@ my %tests = (
 			no_owner                => 1,
 			only_dump_test_schema   => 1,
 			pg_dumpall_dbprivs      => 1,
+			pg_dumpall_exclude      => 1,
 			schema_only             => 1,
 			section_post_data       => 1,
 			test_schema_plus_blobs  => 1,
@@ -2512,6 +2522,7 @@ my %tests = (
 			no_privs                 => 1,
 			no_owner                 => 1,
 			pg_dumpall_dbprivs       => 1,
+			pg_dumpall_exclude       => 1,
 			role                     => 1,
 			schema_only              => 1,
 			section_post_data        => 1,